Propellant energized ground effect machine



Feb. 26, 1963 s; D. ROLLE PROPELLANT ENERGIZED GROUND EFFECT MACHINE Filed March 3, 1961 5 "m 0 I x x 2 2 7 m a a a a in in)... l J

INVENTOR. SYLVAN D. ROLLE BY 61 J.

FM ATTORNEYS United States Patent Filed Mar. 3, 1961, Ser. No. 93,276 Claims. (Cl. 180-7) (Granted under Title 35, U.S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to vehicles which travel in close proximity to a sub-surface and are known as gas-cushion vehicles or ground efiect machines. More particularly, the invention concerns such vehicles which are motivated by gas generating means and wherein the vehicle platform is made completely collapsible.

Heretofore, vehicles of the aforementioned type were energized by motor-driven fans or air pumps. These mechanical devices were so arranged that air, at a low pressure of the order of a few pounds per square foot, was permitted to be directed into the space below the vehicle platform and the sub-surface to maintain the vehicle a short distance above the sub-surface. A portion of this air could then be controllably diverted to nozzles adjustably mounted above or below the platform to provide directed propulsion of the vehicle.

Vehicles of this type possess serious disadvantages. For example, they are bulky and cumbersome due to the weight of the fan or pumping mechanism which necessitates a heavy and rigid platform. Since the primary objective in the design of these vehicles is to achieve a high load transport per pound of fuel ratio, it is apparent that the efficiencies of such vehicles leave much to be desired.

A further disadvantage of current ground efiect machines is their inability to operate satisfactorily under severe arctic conditions which is attributable primarily to the internal combustion engine makeup. Again, these vehicles require considerable space when not in use. The hovering performances of ground eflect machines are improved when their dimensions are increased.

Briefly, I am able to overcome these and other dis-- advantages by employing a solid or liquid rocket-like propellant in a gas generator as the energizing means and an ejector, or a plurality of ejectors, cooperating therewith for augmenting the propulsive and/ or lifting thrust. Since there are no moving parts to my inventive device, the platform may adequately be fabricated from a light-weight material and fully collapsible or inflatable.

It is therefore a broad object of this invention to provide an efficient ground effect machine.

Another object of the invention is to provide such a machine which is lighter in weight than currently known or used ground effect machines.

A further object of the invention is to provide a ground effect machine, which, when fully collapsed, is a compact, light-weight structure, and yet capable of being thus stored for long periods of time without requiring inspection or suffering deterioration.

Still another object of the invention is to provide a ground effect machine which is equally operable in moderate, arctic or tropic atmospheres and which can be readied for use in very short periods of time.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures and wherein:

FIG. 1 is a simplified diagrammatic view, partly in vertical section, of an embodiment of the invention employing a single ejector only;

FIG. 2 is a view of the embodiment illustrated in FIG. 1 looking up from the bottom, showing one of the collapsing means partially extended; and

FIG. 3 is a modification of the collapsing means of FIG. 2, with details omitted.

Referring now to the drawings, there is shown generally at 10 a ground efiect machine having a support platform 11 made of a strong pliable fabric. The platform has a flexible curtain 12 depending therearound which is conveniently a resilient material such as rubber, or optionally, may partake of a brush-like material, which functions to aid in retaining the pressure between the platform and the sub-surface. A hub 13, centrally located of the platform 11 and rigidly secured thereto, has a plurality of radially extending telescoping members 14 circumferentially spaced therearound for extending the platform when ready for use. The telescoping members are illustrated as being below the platform but, if desired, may be enclosed completely within the platform fabric. The outer telescoping elements are connected to the platform fabric at 15 while the inner elements are secured to the hub at 16, both of which may be achieved by any well known methods.

FIG. 2 clearly illustrates the collapsibility of my inventive device, it being apparent from the drawing that when the lower left hand telescoping member is caused to be fully extended, the platform will be in operable condition, or as shown by the dotted lines.

Each set of telescoping tubes may optionally contain an actuating cartridge therein, much like the Aircraft Personnel Catapult or canopy remover, for extending the tubes when the respective cartridges are fired. The Aircraft Personnel Catapult and canopy remover are described in the September 1955 publication of Aeronautical Engineering Review in an article entitledFEscape From High-Speed Aircraf by R. Frost. The telescoping tube structure, shown herein has been found to be equally applicable to the peripheral jet type ground effect machine.

An ejector 17 is mounted through the platform and is illustrated concentrically disposed within hub 13 although it may desirably be positioned outside the hub. It will be understood, of course, that a plurality of ejectors will normally be employed in the practice of my invention.

Ejector 17 is conventional, having a primary nozzle (not shown) to which is supplied, through a high pres sure passageway 18, a gas at a pressure of the order of 1000 psi. from a gas generator 20, suitably supported on platform 11 by a brace 21. The generator may contain a solid or liquid propellant which is actuated by a mechanical or electric igniter 22. The ejector has the customary air inlet 23 through which ambient air is entrained by the propellant gas to be exhausted downwardly through the ejector diffuser at much lower temperatures and pressures than that of the entering propellant gas. Additionally, if the mixing process within the ejector is is efiicient, i.e., the air is mixed with the propellant gas in the ratio of about 10 to 1, the momentum of the mixed streams will far exceed that of the propellant gas to provide increased thrust of the vehicle.

A portion of the propellant gas may be controllably diverted from passageway 18 into adjoining passageway 24 by means of valve 25, and then exhausted through propulsion nozzle 26 to provide cruise performance to the vehicle. The propulsion nozzle may similarly be an ejector-type device, and is pivotally mounted at 27 to tube 18 by any well known methods for varying the direction of thrusto'f the machine.

In the modification of FIG. 3, the telescoping tubes have been replaced by appendages 28 which are hinged at 29 to permit extension thereof as shown generally at 30. The appendages are secured to the hub and platform analogous to telescoping members 14 of FIG. 2.

In the operation of my inventive vehicle, platform 11 is allowed to become fully extended through the telescoping tube or appendage assembly and the gas generator'propellant ignited. The generator gas is fed into the ejector through tube 18 and is mixed with the air entering the ejector air inlet 23, and thence discharged through the dilfuser. Since the ground effect machine is capable of traveling over sub-surfaces including combustible terrain, such as dried grass and the like, the ejector serves an added purpose of lowering the discharge temperature of the hot propellant gases to about 200 F. These cooler discharged gases also aid in preventing the fabric platform from igniting, are less hazardous to the vehicle operator, and in military maneuvers, offer no undesirable'night-time signatures. When the platform has been sufficiently raised over the sub-surface, a small quantity of the propellant gases may be controllably exhausted from the propulsion nozzle to provide directional thrust to. the vehicle.

By way of further explanation, the following example is cited for the purpose of illustrating a typical ground effect machine of the present invention, it being understood that the invention is not to be considered as being limited to the specific variables selected. As it will be apparent to those skilled in this art, a wide variety of propellants, platform materials, etc., such as disclosed hereinbefore may be employed in the device contemplated herein:

Propellant-solid, nitroglycerine-nitrocellulose Igniter-electric Ejectors-one; single nozzle; difiuser angle at 20 using Blowing Boundary Layer Control Platform fabric reinforced nylon; when extendedabout 10 x 8 feet Collapsestructure4 telescoping tube assemblies, ex-

posed underneath platform, cartridge actuated Flexible curtain /2" rubber A ground elr'ect machine made in accordance with the afore-described conditions and having about 54 pounds propellant, has been found adequate to propel a 400 pound payload about 5 miles at approximately 60 mph. It should be noted that the entire device, exclusive of the payload, will weigh only about 200 pounds.

In comparison therewith, a present art machine capable of similar transport, and using a gasoline engine with fan and accessories, will weigh about 300 pounds exclusive of any payload. 1

From the foregoing, it is apparent that through my inventive device, I have provided a unique ground effect machine which is characterized by its extreme lightness in weight, inherent reliability under severe atmospheric conditions and its ability to be stored compactly for extended periods and yet be capable of being readied for emergency use in the shortest intervals of time.

I claim:

1. In a collapsible light-weight ground effect machine, said machine being devoid of fans, pumping mechanisms, engines and moving parts, the combination comprising a pliable platform, a flexible curtain peripherally depending from said platform, gas generating means supported on the platform and containing a propellant, other means for igniting said propellant, an ejector receiving gases generated by the propellant and having a diffuser exhausting said gases to the underside of said platform, a propulsion nozzle mounted above the platform in communicating relation with the generator, 2. central hub affixed to the platform, a plurality of spaced radially extensible members fastened to said hub, each of said members having its outermost portion secured to a corresponding section of the platform periphery.

2. The device of claim 1 wherein each of said radially extensible members comprises telescoping tubes for collapsing the machine into a compact unit.

3. The device of claim 1 wherein each of said radially extensible members comprises hinged appendages for collapsing the machine into a compact unit.

4. The device of claim 1 further characterized by a control valve interposed between the gas generator and propulsion nozzle. 7

5. The device of claim 4 further characterized by a pivotal connection between said gas generator and control valve, said connection providing directional thrust to said machine.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Publication: Aviation Week; July 6, 1959; pages and 116.

Publication: Design News; May 23, 1960; pages 6 and 7. 

1. IN A COLLAPSIBLE LIGHT-WEIGHT GROUND EFFECT MACHINE, SAID MACHINE BEING DEVOID OF FANS, PUMPING MECHANISMS, ENGINES AND MOVING PARTS, THE COMBINATION COMPRISING A PLIABLE PALTFORM, A FLEXIBLE CURTAIN PERIPHERALLY DEPENDING FROM SAID PLATFORM, GAS GENERATING MEANS SUPPORTED ON THE PLATFORM AND CONTAINING A PROPELLANT, OTHER MEANS FOR IGNITING SAID PROPELLANT, AN EJECTOR RECEIVING GASES GENERATED BY THE PROPELLANT AND HAVING A DIFFUSER EXHAUSTING SAID GASES TO THE UNDERSIDE OF SAID PLATFORM, A PROPULSION NOZZLE MOUNTED ABOVE THE PLATFORM IN COMMUNICATING RELATION WITH THE GENERATOR, A CENTRAL HUB AFFIXED TO THE PLATFORM, A PLURALITY OF SPACED RADIALLY EXTENSIBLE MEMBERS FASTENED TO SAID HUB, EACH OF SAID MEMBERS HAVING ITS OUTERMOST PORTION SECURED TO A CORRESPONDING SECTION OF THE PLATFORM PERIPHERY. 